This invention relates generally to neonatal patient treatment devices, and more particularly to a thermal support device for maintaining appropriate temperature of an infant.
Incubators and radiant warmers have both been used to maintain the appropriate body temperature of small or premature infants. An incubator provides an enclosure, generally transparent, within which heated air is circulated to minimize heat loss of the infant. Heat is transferred to the infant via convective heat transfer. A major drawback of the typical incubator is that it provides for only limited access by a care provider to the infant. More particularly, the incubator typically provides a large access door for placing the infant into or removing the infant from the incubator. However, it will be appreciated that opening such a door causes rapid cooling of the interior of the infant, and therefore should be opened as seldom as possible in order to maintain the appropriate temperature of the incubator interior and hence the infant. Thus, most incubators are provided with means of supplemental access in the form of hand ports or small entry doors for routine care of the infant to minimize heat loss during care of the infant. Such small entry doors and hand ports, however, are quite limiting in that a care provider does not have complete access to and mobility with respect to an infant within the incubator.
Radiant warmers, on the other hand, provide for continuous and open access to an infant to accommodate a high frequency of care provider intervention. In radiant warmers heat is transferred to the infant via radiative heat transfer. Radiant warmers typically include infrared heaters which emit infrared energy which is absorbed by the skin of the infant. The infrared heater is typically mounted to a support which is suspended above the infant support surface of the radiant warmer. There is no canopy or enclosure as in incubators. Radiant warmers thus provide open access to infants requiring surgery, for example, or other procedures requiring multiple care providers to have access to an unobstructed sight of the infant. However, while incubators are typically provided with humidification mechanisms to raise the level of relative humidity within the incubator, thus contributing to a reduction in heat loss from evaporation of fluids from the infant, radiant warmers due to their open nature and the mode of heat transfer employed cause infant evaporative water losses which are significantly greater than those encountered by an infant within an incubator. Another disadvantage of the radiant warmer, when compared to an incubator, is that the infant is directly exposed to ambient nursery contaminants in the form of noise and unfiltered air. The incubator, on the other hand, being an enclosure for the infant, reduces the effects of nursery environmental conditions on the infant.
It has therefore been an objective of the present invention to improve upon prior art incubators by providing an incubator which will maintain the appropriate temperature of a premature infant via convective heat transfer yet which will also increase caregiver access to the infant.
It has been another objective of the present invention to combine the advantages of each of the prior art types of incubators and radiant warmers into a single infant warming device, which combination exploits the advantages of each of these two types of prior art devices but as well avoids the inherent disadvantages in them when employed singly.
In accordance with the objectives of the present invention and a preferred embodiment thereof, the present invention comprises, in its broadest form, an infant thermal support device providing convective heat transfer to the infant similar to an incubator, yet which allows for unlimited care provider access to an infant, and without compromising the infant""s thermal environment. The invention provides an infant support having head and foot ends and lateral sides, with the support providing a heated curtain of air traveling over an infant on the support to maintain the temperature of the infant""s skin at an appropriate level. The support provides curtains of air traveling upwardly from the lateral sides and at least one of the ends of the support. The warming device provides warmth to the infant on the support by virtue of the heated air curtain, and the upwardly oriented air curtains reduce perturbations of the heated air curtain caused by physical disturbances adjacent the device such that the device does not require a canopy enclosing the device to maintain the infant warm. Thus, the device provides unlimited caregiver access to an infant supported on the support, while maintaining the appropriate temperature of the infant by a convective mode of heat transfer.
The device in its preferred form provides three infant thermal environment controlling air curtains, and at least three air curtains protecting the three thermal environment air curtains from perturbations due to physical disturbances adjacent to the device. The first heated air curtain travels from the foot end of the infant support toward the head end of the infant support over an infant supported by the support, at a velocity of up to approximately 0.1 meters per second and temperature of up to about 38-39xc2x0 C. The second and third heated air curtains travel from the lateral edges of the support upwardly and toward one another at approximately 45xc2x0 angles relative to the support and over the infant supported by the support, at a velocity of up to approximately 0.5 meters per second and temperature of up to approximately 38-39xc2x0 C.
The three air curtains which prevent perturbations of the heated air curtains from physical disturbances travel upwardly preferably vertically from the lateral sides and the foot end of the support at a velocity of approximately 1-2 meters per second.
The infant warming device further preferably comprises a canopy mounted over the infant support and adapted to be raised and lowered relative to the support, such that the canopy can be lowered to a lowermost position which substantially encloses the support. The device can then function, with canopy lowered, as a traditional enclosed incubator. With the canopy raised to provide complete and unrestricted access to the infant, the three heated air curtains and three perturbation-reducing air curtains maintain the infant thermal environment.
The device of the present invention further preferably provides an infrared heater mounted above the support and which is adapted to be raised and lowered relative to the support along with the canopy. The device, in this form, is in essence a combination infant radiant warmer and incubator. Thus, the device can function as either a traditional incubator, a traditional radiant warmer, or can function simultaneously as both, with the raisable and lowerable canopy, heated air curtains and perturbation-reducing air curtains and infrared heater maintaining the thermal environment of the infant as desired.
Another feature of the present invention is a heated shelf storage area on the infant support portion of the warmer for storing various items such as probes, probe covers and laryngoscopes.
Yet another feature of the present invention is the provision of a canopy including a light reduction medium for selected darkening of the infant sleep area of the warmer.
A further feature of the present invention is the provision of a motion sensor mounted on the infant support for sensing disturbances around the infant thermal support device, and a controller for controlling the speed of the fan which provides the curtains of air traveling upwardly. The controller, upon the sensor sensing a disturbance, is operable to increase the speed of the fan providing those curtains of air traveling upwardly to further reduce perturbations of the heated air curtain or curtains.
Still a further feature of the present invention is the provision of a position sensor associated with the raisable and lowerable canopy for determining the relative position of the canopy relative to the infant support, and a controller which, upon the sensor sensing the relative position of the canopy with respect to the support, is operable to decrease the speed of the fan providing the upwardly traveling air curtains as the need for those upwardly traveling air curtains diminishes as the canopy is lowered and approaches the infant support, and to decrease the speed of the fan providing the heated air curtains as the need for the heated air curtains diminishes due to the infant becoming substantially enclosed by the support and canopy.
The present invention provides numerous advantages over traditional incubators and radiant warmers, one of which is that the device provides an infant thermal environment very nearly identical to that provided by a traditional incubator, yet which provides totally unrestricted and unlimited access to the infant by a care provider, unlike traditional incubators.
Another advantage of the present invention is that it combines the benefits of both traditional incubators and radiant warmers into a single device, thus exploiting the advantages of both while tending to eliminate the disadvantages when employing either singly.